王坡煤矿陷落柱发育特征及其对煤层气开发的影响

陷落柱是影响煤矿区煤炭与煤层气开发的主要制约因素之一。研究煤矿区陷落柱成因及分布特征,有助于降低煤炭开采与煤层气开发的风险。通过对陷落柱控制因素和发育特征的分析,结合王坡煤矿已发现陷落柱的分布情况,探讨了陷落柱对王坡煤矿煤层气分布及其开发的影响机制。分析认为：陷落柱周围3号煤的气含量有所降低;在煤层气开发过程中,陷落柱可能会贯通奥陶系灰岩层与煤系地层,从而对煤层气的钻井、压裂以及排采工程产生不利影响。     

On the impact of rockfall catch fences on ground-based radar interferometry

Rockfalls are major natural hazards in mountainous regions and as such monitored if they pose a high risk to people or infrastructure. Ground-based radar interferometry is a relatively new technique suitable for such monitoring. It offers the potential for determining sub-mm- to mm-level displacements by remote measurements under various weather conditions. To avoid damage from smaller rocks and debris, critical surfaces are often protected by rockfall catch fences. We present an experimental investigation proving that the radar measurements are indeed significantly affected by a catch fence made of steel even if its mesh size is larger compared to that of the wavelength of the radar. A stable rock wall in a quarry was monitored by means of a ground-based synthetic aperture radar for 2 days. Different fences varying in shape, size, and density of mesh and in various geometrical configurations were erected at different locations for short periods of time during the experiment. We show that for surfaces observed through the fence, the reflected power can be reduced by 20 dB and thus the signal-to-noise ratio is significantly deteriorated. We also observed spurious interferometric phase shifts. Even parts of the rock wall not covered by the fences are affected. Side lobes and mixed pixels result, e.g., in severe loss of coherence and thus potentially mask actual displacements.     

Main features of the fluid regime during the development of earthquake foci

The features of a fluid regime in the focus of an earthquake are considered. During the development of the focus, the fluid regime in its zone depends on the internal movement of fluids and their entry from outside. The main inflow of fluids and the increase in their pressure occur due to ascending filtration through subvertical conductive faults. Fluids may also flow from surface segments, which causes the majority of induced earthquakes. The close relationships between the mechanism of natural earthquakes and the fluids coming from the deep high-pressure zones point to the genetic similarity of degassing and seismicity of the tectonosphere.     

基于强溶蚀带特征的地基岩溶发育程度评价方法

岩溶发育程度评价结论不能合理反映地基实际的岩溶问题处理难度,是导致目前岩溶区建筑基础选型失误屡见不鲜的根本原因。本文以南宁市吴圩国际机场新航站楼为工程背景,分析了现有的岩溶发育程度评价指标的局限性,论证了以强溶蚀带厚度作为岩溶发育程度评价指标的先进合理性,提出了岩溶发育程度评价的建议标准,结果表明:基于地基溶蚀率深度分布曲线划分的地基强溶蚀带,综合考虑了地基的岩面溶蚀和洞隙发育的主要深度范围,其分布特征能反映岩溶地基最为复杂的深度范围,其作为场地岩溶发育程度评价指标是合理的,其岩溶发育程度评价标准建议如下:当强溶蚀带厚度（M）分别为:＜3.0 m,3.0 m≤M≤6.0 m,≥6.0 m时,场地岩溶发育程度可分别判定为岩溶弱发育、中等发育和强发育。      

Common features in the development of powerful long-duration solar X-ray flares

We have begun an investigation of the possible origins of considerable of powerful solar flares. This effect is manifest, first and foremost, in the existence of high-temperature plasma in flare loops over many hours. Analysis of the soft X-ray emission in two energy bands detected by the GOES satellites for about 20 powerful solar flares reveals long time intervals during the decay phase when the source temperature decreases, in general, exponentially. The characteristic time t _i for a decrease in the temperature by a factor of ten is 3–10 hours for most powerful events. In addition, another interval of very slow decrease with a characteristic time t _i of tens of hours can be identified in some cases. We found a gradual change in the dependence of the temperature on the square root of the emission measure for the source as a whole, which characterizes the transition from purely coronal processes to powerful flares with a prolonged inflow of plasma from the chromosphere. Modeling the energy balance in a loop can yield the requirements for the source of plasma heating in a long-lived arch system. A necessary condition for the development of prolonged flares seems to be a powerful coronal mass ejection, which initiates the formation of a source of plasma heating at coronal heights. Our analysis shows that a considerable fraction of the energy is often released in the region of the cusp, and that systems of giant coronal arches rising to heights of about 100 000 km above the limb are formed in most prolonged events (called dynamical flares in the terminology of Svestka).     

鄂尔多斯盆地奥陶系古岩溶发育程度的分形特征

鄂尔多斯盆地奥陶系天然气勘探实践表明,古岩溶发育程度影响着储层优劣,然而对古岩溶发育程度的描述缺少定量化手段。本文利用分形理论对鄂尔多斯盆地奥陶系古岩溶的发育程度进行定量化研究,首先分析了古岩溶的分形特征,进而研究了分形维数的计算方法与实现流程,最后结合钻探资料利用分形维数对工区内古岩溶发育程度进行了定量化描述并分析了其与储层优劣的关系。结果表明,鄂尔多斯盆地奥陶系古岩溶的发育具有分形特征,分形维数反映了古岩溶在一定地质条件下的发育程度,工区内工业气流井的分形维数大于1.65。因此,将分形维数作为衡量古岩溶发育程度的定量指标,无疑会提高古岩溶储层评价的客观性、科学性。      

环渤海区域滩涂资源开发承载力时空演变特征

有效识别和评估各滩涂区域资源开发承载力时空变化的差异,有利于滩涂资源的科学规划,对实现沿海滩涂资源的高效利用与保护具有重要意义。本文针对渤海半封闭海湾滩涂特征的空间差异性,基于“驱动力-状态-影响”模型,构建了滩涂资源开发承载力评估体系,对研究区域7个评价单元在4个代表年份的资源承载力进行了评估,阐明了海湾滩涂资源开发承载力时空演变特征。结果表明：围填工程减弱了渤海湾滩涂资源开发承载能力,工程大规模建设期间(2003—2012年)各评价单元承载力均呈下降趋势,2012年后随着国家围填海管控措施的实施,滩涂承载力有回升态势;在空间上滩涂资源承载力表现为湾顶的降幅高于海湾南部区域,滩涂开发前后天津港附近区域承载力较弱,黄骅港以南滩涂养殖区承载力较强。     

国内主要航空物探飞行平台特点及发展

航空物探是将航空地球物理勘探仪器搭载在不同飞行器上,通过特定的飞行作业方式开展的地球物理勘查技术。航空物探的勘查效果同时受物探仪器性能和所采用的飞行平台及其飞行控制效果的双重影响。根据不同的需求,合理地选择并运用飞行器,是开展航空物探测量工作需要解决的首要任务。笔者在回顾国内航空物探发展的基础上,将主要使用的航空物探飞行器分为固定翼、直升机、无人机及其他等四类,分析每类飞行器作为航空物探搭载平台的优缺点,从持续服务地质勘查的需要出发,展望了航空物探及搭载平台的主要发展方向。     

地面回线源瞬变电磁法一维反演系统及其应用

瞬变电磁法现阶段的资料处理解释仍以一维反演为主,因此开发一套功能齐全、高效稳定的一维反演系统对进一步提高国内瞬变电磁法的应用水平仍具有重要意义。本研究开发的地面回线源瞬变电磁法一维反演系统包括了基于高斯牛顿法的最小构造反演和Occam反演,也包括了基于阻尼最小二乘法的横向约束反演和空间约束反演。以内蒙古那仁宝力格煤田玄武岩岩体形态探测为例,将该反演系统的最小构造反演和Occam反演结果与商业软件IX1D进行了对比验证,发现不同反演方法获取的电阻率二维断面图中,玄武岩岩体形态相似、电阻率范围一致;结合钻孔资料,这些一维反演结果清晰反映了玄武岩岩体除岩浆上涌通道区域外的分布形态。将横向约束反演和空间约束反演应用于该实例,结果表明:相邻测点间玄武岩岩体电阻率差异缩小,玄武岩与沉积岩界面的连续性得到增强。     

冰雪消融期松花江哈尔滨段干流水动力模拟及其时空分布特征分析

受春季冰雪消融的影响,我国北方地区的河流会形成桃花汛期,期间河流的水位、水深和流场较其它季节会发生较大变化,从而对流域水环境管理和水资源保护的利用产生影响.为科学地对松花江哈尔滨段在冰雪消融期水动力变化情况进行分析,利用ArcGIS 10.0对DEM影像进行矢量化,在Delft3D-RGFGRID中创建正交曲线网格,基于EFDC模型建立松花江哈尔滨市段二维河流数值水动力模型.模拟了2014年1月-10月间的整个河段不同时空条件下的水动力变化情况,根据哈尔滨市水文站2013年、2014年实测数据对模型的参数和模拟结果进行率定和验证,模拟水位与实测水位最大相差0.33 m,相对误差<10%,吻合度高.模拟结果表明:整个江段平均水位在桃花汛期可达116.38 m,丰水期进一步上升至116.54 m,枯水期为115.64 m,平水期为116.23 m.朱顺屯和阿什河口断面水深在丰水期都明显大于桃花汛期,呼兰河口和大顶子山断面两汛期的水深几乎持平,大顶子山断面水深在各时期都较浅,附近易发生冰塞.朱顺屯、阿什河口、呼兰河口大顶子山桃花汛期流速分别为0.55、0.61、0.43、0.57 m·s^-1;丰水期流速分别为0.59、0.66、0.47、0.63 m·s^-1,各断面桃花汛期的流速与丰水期流速相当,略小于丰水期,流向平稳无涡旋.该模型可以较好的模拟河道水力要素随时间及空间演变规律,以便在不同典型水文年进行水力模拟和预测,可为松花江冬春季通航管理、水资源配置、水质模拟、水质目标管理、水环境容量计算和污染物总量减排提供决策依据.     

2001-2012年新疆融雪型洪水时空分布特征

利用2001-2012年新疆区域内发生的融雪型洪水资料,分析研究了近12 a新疆融雪型洪水时空分布特征.结果表明:新疆融雪型洪水与前一年10月至当年3月新疆全站总累计降水量大小相关,降水量大的年份,对应的融雪型洪水发生次数也多;冬末至夏季融雪型洪水在北疆地区基本上是从西向东、从南向北的先后顺序出现,而在南疆地区的融雪洪水基本上是从西向东、从北向南先后顺序出现.新疆融雪型洪水主要集中出现在春夏季,其中,北疆地区在3月,南疆地区在7月发生较多;伊犁河谷、昌吉、阿勒泰、和田等地区及青河、乌鲁木齐、阿克陶、民丰等市县是新疆融雪型洪水的高发区.     

Monitoring the temporal development of natural hazard risks as a basis indicator for climate change adaptation

The potential effects of climatic changes on natural risks are widely discussed. But the formulation of strategies for adapting risk management practice to climate changes requires knowledge of the related risks for people and economic values. The main goals of this work were (1) the development of a method for analysing and comparing risks induced by different natural hazard types, (2) highlighting the most relevant natural hazard processes and related damages, (3) the development of an information system for the monitoring of the temporal development of natural hazard risk and (4) the visualisation of the resulting information for the wider public. A comparative exposure analysis provides the basis for pointing out the hot spots of natural hazard risks in the province of Carinthia, Austria. An analysis of flood risks in all municipalities provides the basis for setting the priorities in the planning of flood protection measures. The methods form the basis for a monitoring system that periodically observes the temporal development of natural hazard risks. This makes it possible firstly to identify situations in which natural hazard risks are rising and secondly to differentiate between the most relevant factors responsible for the increasing risks. The factors that most influence the natural risks could be made evident and eventual climate signals could be pointed out. Only with this information can the discussion about potential increases in natural risks due to climate change be separated from other influencing factors and be made at an objective level.     

The role and performance of ground-based networks in tracking the evolution of the ozone layer

In the 1980s, ground-based monitoring of the ozone layer played a key role in the discovery of the Antarctic Ozone Hole as well as in the first documentation of significant winter and spring long-term downward trends in the populated mid-latitude regions. The article summarizes the close-to-hundred-year-long history of ground-based measurements of stratospheric ozone, and more recent observations of constituents that influence its equilibrium. Ozone observations began long before the recognition of the impact of increasing emissions of manmade ozone-depleting substances on ozone and therefore on UV levels, human health, ecosystems and the Earth climate. The historical ozone observations prior to 1980s are used as a reference for the assessments of the state of the ozone layer linked to the enforcement of the Montreal Protocol. In this paper, we describe the worldwide monitoring networks and their ozone observations used to determine long-term trends with an accuracy of a few percent per decade. Since 1989, the ground-based monitoring activities have provided support for the amendments of the Montreal Protocol (MP). They include monitoring of (a) the ozone total column and the vertical distribution at global scale, (b) the ozone-depleting substances (ODS) related to the MP such as chlorofluorocarbons (CFCs), and their decomposition products in the stratosphere, and (c) the atmospheric species playing a role in ozone depletion, e.g., nitrogen oxides, water vapor, aerosols, polar stratospheric clouds. We highlight important accomplishments in the atmospheric monitoring performed by the Global Atmosphere Watch program (GAW) run under the auspices of the World Meteorological Organization (WMO) and by the Network for the Detection of Atmospheric Composition Change (NDACC). We also address the complementary roles of ground-based networks and satellite instruments. High-quality ground-based measurements have been used to evaluate ozone variabilities and long-term trends, assess chemistry climate models, and check the long-term stability of satellite data, including more recently the merged satellite time-series developed for the detection of ozone recovery at global scale, which might be further modified by climate change.     

Characterisation of the environmental impact of the Rodalquilar mine,Spain by ground-based reflectance spectroscopy

This study has investigated the utility of using field-based reflectance spectroscopy to characterise the distribution and nature of the dispersion of tailings material from the Rodalquilar mine, Spain. Field spectral measurements covering the visible to shortwave infrared wavelengths (0.35 to 2.5 m) and laboratory analyses were performed on samples collected along the length of the main river within the Rodalquilar valley. The nature and degree of contamination at locations within the river channel were calculated by a range of spectrometric analyses. The resulting mineral maps identified that tailings material with significant amounts of hematite with minor jarosite, ferrihydrite and goethite, and clays, primarily alunite and kaolinite, with minor smectite and illite, had been dispersed along the length of the river. These results have been used to improve understanding of the erosion and remediation history of the Rodalquilar mine. This study has shown the potential of field-based reflectance spectroscopy, integrated with ground positioning and digital mapping systems, as a real-time mapping methodology enabling immediate, accurate characterisation of the nature and scale of tailings material dispersion.     

新安江流域2000—2021年NDVI时空变化特征及其影响因素分析

新安江流域是长三角地区重要的生态屏障,对该流域的植被覆盖情况进行监测并掌握其动态变化特征,对该区生态环境保护具有重要意义。以新安江流域为研究区,利用2000—2021年MOD13Q1数据,针对归一化植被指数(NDVI)的时空变化特征及其变化的持续性,使用Theil-Sen Median趋势分析、Mann-Kendall检验和Hurst指数等方法进行分析,探讨了NDVI的变化趋势与岩性建造、土地利用类型之间的关系。结果表明:二十多年以来,新安江流域的年平均NDVI为0.5~0.9,总体呈波动上升趋势,最大值出现在每年7—9月,最小值出现在每年1—3月,呈现"山地高,丘陵和平原较低"的分布特征。NDVI变化类型以改善型为主,改善型区域面积占比>70％,且以持续改善型为主,其中轻微改善型和明显改善型面积占比达85.71％。第四系和白垩纪红层分布区,NDVI严重退化和轻微退化占比较高,NDVI退化情况较严重的土地利用类型为建设用地、草地和耕地。该研究结果可反映新安江流域NDVI的时空变化特征,对于该区生态环境保护与建设具有一定指导意义。     

Evolution of the modern Nile delta promontories: development of accretional features during shoreline retreat

The active accretional features that have developed along the modern Nile Delta promontories during shoreline retreat are analysed using topographic maps, remote imagery, ground and hydrographic surveys, together providing 15 time-slice maps (1922–2000) at Rosetta and 14 time-slice maps (1909–2000) at Damietta. Small double sandy spits developed and persisted at Rosetta between 1986 and 1991. At Damietta, a much larger single spit, 9 km long, formed approximately east of the mouth of the Damietta Nile branch between 1955 and 1972, although its source has now been depleted. Both the Rosetta and Damietta inlets are associated with submerged mouth bars that accumulated prior to the damming of the Nile, but that continue to contribute to local sedimentation problems, particularly at Rosetta. The development of the active accretional features along the Nile promontories reflects a combination of factors including sediment availability, transport pathways from source areas, a decrease in the magnitude of Nile flood discharges, as well as the impact of protective structures at the river mouths.     

GIS-based spatial and temporal prediction system development for regional land subsidence hazard mitigation

An integrated GIS-based approach for establishing a spatial and temporal prediction system for groundwater flow and land subsidence is proposed and applied to a subsidence-progressed Japanese coastal plain. Various kinds of fundamental data relating to groundwater flow and land subsidence are digitized and entered into a GIS database. A surface water hydrological cycle simulation is performed using a GIS spatial data operation for the entire plain, and the spatial and temporal groundwater infiltration quantity is hereby obtained. Through the data transformation from the GIS database to a groundwater flow code (MODFLOW), a 3D groundwater flow model is established and unsteady groundwater flow simulation for the past 21 years is conducted with results which compare satisfactorily with observed results. Finally, a Visual Basic code is developed for land subsidence calculations considering aquifer and aquitard deformation. Future land subsidence in the plain is predicted assuming different water pumping scenarios, and the results provide important information for land subsidence mitigation decision-making.     

蜀南地区茅口组古岩溶地貌与缝洞系统发育关系研究

蜀南地区茅口组古岩溶地貌形态对缝洞系统的发育起着控制作用。在恢复茅口组古地貌的基础上,根据上二叠统在区域上的分布厚度、风化壳表面侵蚀特征和茅口组地层保存程度,将茅口组顶部古岩溶面划分为岩溶台地、岩溶坡地(又分为西部陡坡带和北东部缓坡带)和岩溶盆地3个二级地貌单元;研究了各地貌单元和缝洞系统发育关系。结果表明:岩溶台地岩溶水以垂向渗流为主,风化剥蚀强烈,形成垂向的溶缝、溶洞常被泥质等充填,横向连通性弱;岩溶陡坡、岩溶台地和岩溶陡坡过渡带岩溶作用最强,溶孔、溶洞发育,且充填程度低,缝洞系统最为发育,是有利的勘探区带;岩溶缓坡水流速度慢,岩溶作用周期长,溶蚀空间易受充填,不利于缝洞保存;岩溶盆地岩溶发育最弱,储集性能差,是不利的勘探区带。      

High temporal and spatial resolution observations of meso-scale features of pre- and mature summer monsoon cloud systems over Bangladesh

Meso-scale characteristics of disturbances that bring about atmospheric disasters in pre- and mature monsoon seasons in Bangladesh are analyzed. Several types of meteorological instruments capable of observations with high temporal and spatial resolutions were introduced for the first time in this area to capture the meso-scale structure of rainfall systems. We installed an automatic weather station (AWS) and several automatic raingauges (ARGs) and utilized the weather radar of Bangladesh Meteorological Department (BMD). From the radar image in the summer of 2001 (16–18 July), a striking feature of the systematic diurnal variation in this area was elucidated. In these 3 days, the diurnal evolutions of convective activity were remarkably similar to each other, implying that this pattern can be understood as a typical response of local cloud systems to the diurnal variation of insolation under some summer monsoon situations. The ARG data show the difference in characteristics of rainfall between pre- and mature monsoon seasons. The short intense downpour tends to occur more frequently in the pre-monsoon season than in the mature monsoon season. The pre-monsoon rainfall also has clear diurnal variation with a peak that is more strongly concentrated in time. In the northern part the rainfall peak is found in between midnight and early morning, while it is observed in the daytime in central to western parts of the country. Two disaster cases caused by meso-scale disturbances are analyzed. Although they occurred in the same season, the structures of the cloud systems were largely different from each other. The disturbance brought about tornadoes on 14 April 2004, consisting of many spherical cloud systems of approximately 20 km size. On the other hand, another one that caused the tragic river water transport accident on 23 May 2004 had meso-scale rain band structure. The latter case was captured by the AWS located at Dhaka. Sudden changes in temperature, wind and pressure were observed clearly, showing the typical structure of convective rain bands.